FUNCTION OF THE TRANSCRIPTIONAL REGULATING PROTEIN OF 132 kDa (TReP-132) ON HUMAN P450scc GENE EXPRESSION

Cytochrome P450scc catalyzes the important first step in the steroid synthesis pathway; however, it is clear that additional factors regulating the temporal and spacial specific expression of the CYP11A1 gene remain to be identified. To isolate novel transcription factors that regulate this gene, a cis-acting element of the 5′-flanking region from nucleotides −155 to −131 (−155/−131) was used to screen a human placental λgt11 cDNA expression library, and an interacting clone was isolated. The open reading frame of the cDNA encodes several domains that are characteristic of transcription factors including an acidic region, a region rich in prolines and three zinc-finger motifs. Expression of the cDNA by in vitro transcription/translation and by transient transfection in HeLa cells yielded a protein of 132 kDa, which concurs with the predicted size. Transfection of the cDNA in placental JEG-3 and adrenal NCI-H295 cells, stimulate expression of a reporter construct controlled by the P450scc gene 5′-flanking region from nucleotides −1676 to +49. This transcriptional regulating protein of 132 kDa (TReP-132) when expressed in HeLa cells was demonstrated to interact with the −155/−131 region in bandshift analysis, and tandem copies of this region was shown to confer activation of the heterologous HSV thymidine kinase minimal promoter. Coexpression of CBP/p300 with TReP-132 further increased promoter activity, and the proteins were demonstrated to interact physically. RNA analysis demonstrated the highest levels of expression in the adrenal cortex and testis; and transcript expression is also found in the steroidogenic JEG-3, NCI-H295, and MCF-7 cell lines, but not in non-steroidogenic HepG2 and HK293 cells. Subsequently it has been shown that TReP-132 interacts with steroidogenic factor-1 (SF-1) through specific domains; and along with the interaction with CBP/p300 these factors are postulated to form a complex to regulate expression of the P450scc gene.

[1]  D. Hum,et al.  The Transcriptional Regulating Protein of 132 kDa (TReP-132) Enhances P450scc Gene Transcription through Interaction with Steroidogenic Factor-1 in Human Adrenal Cells* , 2002, The Journal of Biological Chemistry.

[2]  Y. Labrie,et al.  AIbZIP, a novel bZIP gene located on chromosome 1q21.3 that is highly expressed in prostate tumors and of which the expression is up-regulated by androgens in LNCaP human prostate cancer cells. , 2002, Cancer research.

[3]  D. Hum,et al.  A Novel Zinc Finger Protein TReP-132 Interacts with CBP/p300 to Regulate Human CYP11A1 Gene Expression* , 2001, The Journal of Biological Chemistry.

[4]  M. C. Hu,et al.  Functions of the upstream and proximal steroidogenic factor 1 (SF-1)-binding sites in the CYP11A1 promoter in basal transcription and hormonal response. , 2001, Molecular endocrinology.

[5]  H. Dyson,et al.  Molecular basis for modulation of biological function by alternate splicing of the Wilms' tumor suppressor protein. , 2000, Proceedings of the National Academy of Sciences of the United States of America.

[6]  W. Miller,et al.  Cloning of Factors Related to HIV-inducible LBP Proteins That Regulate Steroidogenic Factor-1-independent Human Placental Transcription of the Cholesterol Side-chain Cleavage Enzyme, P450scc* , 2000, The Journal of Biological Chemistry.

[7]  W. Jiang,et al.  Identification and localization of MEP1A-like sequences (MEP1AL1-4) in the human genome. , 1999, Biochemical and biophysical research communications.

[8]  I. Pikuleva,et al.  Cytochromes P450 in synthesis of steroid hormones, bile acids, vitamin D3 and cholesterol. , 1999, Molecular aspects of medicine.

[9]  A. Lamond,et al.  WT1 interacts with the splicing factor U2AF65 in an isoform-dependent manner and can be incorporated into spliceosomes. , 1998, Genes & development.

[10]  G. Hammer,et al.  Wilms' Tumor 1 and Dax-1 Modulate the Orphan Nuclear Receptor SF-1 in Sex-Specific Gene Expression , 1998, Cell.

[11]  D. Monté,et al.  Regulation of the Human P450scc Gene by Steroidogenic Factor 1 Is Mediated by CBP/p300* , 1998, The Journal of Biological Chemistry.

[12]  David M. Heery,et al.  A signature motif in transcriptional co-activators mediates binding to nuclear receptors , 1997, Nature.

[13]  B. Schimmer,et al.  Steroidogenic factor 1: a key determinant of endocrine development and function. , 1997, Endocrine reviews.

[14]  G. Chrousos,et al.  Steroidogenic factor 1 messenger ribonucleic acid expression in steroidogenic and nonsteroidogenic human tissues: Northern blot and in situ hybridization studies. , 1997, The Journal of clinical endocrinology and metabolism.

[15]  M. Ito,et al.  DAX-1 inhibits SF-1-mediated transactivation via a carboxy-terminal domain that is deleted in adrenal hypoplasia congenita , 1997, Molecular and cellular biology.

[16]  D. Hum,et al.  Transcription of the human genes for cytochrome P450scc and P450c17 is regulated differently in human adrenal NCI-H295 cells than in mouse adrenal Y1 cells. , 1997, The Journal of clinical endocrinology and metabolism.

[17]  T. Gibson,et al.  The SANT domain: a putative DNA-binding domain in the SWI-SNF and ADA complexes, the transcriptional co-repressor N-CoR and TFIIIB. , 1996, Trends in biochemical sciences.

[18]  J. Milbrandt,et al.  Mice deficient in the orphan receptor steroidogenic factor 1 lack adrenal glands and gonads but express P450 side-chain-cleavage enzyme in the placenta and have normal embryonic serum levels of corticosteroids. , 1995, Proceedings of the National Academy of Sciences of the United States of America.

[19]  K. Morohashi,et al.  Function and distribution of a steroidogenic cell-specific transcription factor, Ad4BP , 1995, The Journal of Steroid Biochemistry and Molecular Biology.

[20]  K. Miyagawa,et al.  Subnuclear localization of WT1 in splicing or transcription factor domains is regulated by alternative splicing , 1995, Cell.

[21]  P. Aza-Blanc,et al.  Characterization of placental transcriptional activation of the human gene for P450scc. , 1995, DNA and cell biology.

[22]  W. Herr,et al.  The Oct-2 glutamine-rich and proline-rich activation domains can synergize with each other or duplicates of themselves to activate transcription , 1994, Molecular and cellular biology.

[23]  M. Green,et al.  DNA-binding domains: targets for viral and cellular regulators. , 1994, Current opinion in cell biology.

[24]  S. Honda,et al.  Ad4BP regulating steroidogenic P-450 gene is a member of steroid hormone receptor superfamily. , 1993, The Journal of biological chemistry.

[25]  D. Hum,et al.  Identification of positive and negative placenta-specific basal elements and a cyclic adenosine 3',5'-monophosphate response element in the human gene for P450scc. , 1992, Molecular endocrinology.

[26]  K. Parker,et al.  Steroidogenic factor I, a key regulator of steroidogenic enzyme expression, is the mouse homolog of fushi tarazu-factor I. , 1992, Molecular endocrinology.

[27]  W. Bickmore,et al.  Modulation of DNA binding specificity by alternative splicing of the Wilms tumor wt1 gene transcript. , 1992, Science.

[28]  T. Unger,et al.  p53: a transdominant regulator of transcription whose function is ablated by mutations occurring in human cancer. , 1992, The EMBO journal.

[29]  W. Herr,et al.  Promoter-selective activation domains in Oct-1 and Oct-2 direct differential activation of an snRNA and mRNA promoter , 1992, Cell.

[30]  K. Parker,et al.  A shared promoter element regulates the expression of three steroidogenic enzymes. , 1991, Molecular endocrinology.

[31]  T. Curran,et al.  Binding of the Wilms' tumor locus zinc finger protein to the EGR-1 consensus sequence. , 1990, Science.

[32]  E. A. O'neill,et al.  The proline-rich transcriptional activator of CTF/NF-I is distinct from the replication and DNA binding domain , 1989, Cell.

[33]  R. Tjian,et al.  Transcriptional regulation in mammalian cells by sequence-specific DNA binding proteins. , 1989, Science.

[34]  A. E. Sippel,et al.  Viral myb oncogene encodes a sequence-specific DNA-binding activity , 1988, Nature.

[35]  A. E. Sippel,et al.  The highly conserved amino‐terminal region of the protein encoded by the v‐myb oncogene functions as a DNA‐binding domain. , 1987, The EMBO journal.

[36]  M. Waterman,et al.  Control of gene expression of adrenal steroid hydroxylases and related enzymes. , 1986, Endocrine research.